These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 1.01 s (backtrack: 0/20).

[ebuild  N     ] sci-electronics/ngspice-46::gentoo  USE="X klu openmp readline shared -debug -deprecated -doc -examples -fftw -tcl -test" 10259 KiB

Total: 1 package (1 new), Size of downloads: 10259 KiB